Electricity Production & Storage- Corrections
In the following piece "Why Salt is This Power Plant's Most Valuable Resource" for Smithsonianmag.com I inaccurately described how electricity is produced in the first three paragraphs. I regret the errors.
Power companies are not always making more power than they expect you to consume; they make exactly what you demand. They have enough power plants and technical know-how to make exactly the right amount of electricity at the moment it is demanded by homes, businesses, schools, and hospitals on the grid.
There are enough power plants to provide electricity during peak moments, meaning at other times, when demand is lower, some power plants are shut off and sit idle. This can happen, for example, when wind turbines are spinning hard but demand is low and a nuclear plant or a coal plant is already providing sufficient power. The coal and nuclear plants take longer to shut down and start up again.
If power from the wind farms is not needed, the wind farms may be shut down, instead of the coal or nuclear plants, and the potential energy is effectively wasted, along with the environmental benefit.
The swing in energy demand and the longer shutdown and startup times for baseload power plants discourage the use of some renewables, specifically wind power, which is generated mostly at night when winds are strongest. In short, a lot of electricity, and importantly, clean electricity, is produced at the wrong time.
That’s where energy storage comes in. Storing energy when it's made and releasing it when it's needed helps keep the grid reliable and paves the way for introducing intermittent renewables like wind and solar to the mix.